Nowadays, the increasingly rampant influenza virus is closely related to respiratory diseases and some systemic diseases thereof. With an enormous population and particular living habits which are liable to transmit the virus, China is one of the countries with a high incidence of influenza. The average annual incidence per capita ranges from 0.3 to 0.7 times, let alone 2-4 times in focus groups.
The influenza severely threatens our human existence. Especially speaking, the new varieties of influenza virus, can not only cause other secondary microbial infections, but also directly lead to organ damages and allergic reactions causing death.
Unfortunately, the current therapies, such as inflammatory reaction treatment according to the corresponding clinical symptoms offer only palliative care. Currently, the most common methods for preventing and treating influenza are vaccinating, taking nonspecific antiviral Chinese traditional medicine and administrating a kind of neuraminidase inhibitor—oseltamivir phosphate (Tamiflu). However, the drawbacks of influenza vaccination lie in its' group selectivity, low protective rate and short protective period for only 3-6 months.
At present, although claimed to have antiviral effect, most nonspecific antiviral Chinese medicines are not against the influenza virus and their antiviral act mechanism still remains unknown.
Our previous studies on the treatments of Pathogenic cold indicate that not all Chinese traditional medicines have a definite effect on inhibiting the influenza virus.
As a neuraminidase inhibitor, “oseltamivir phosphate (Tamiflu, (3R,4R,5S)-4-acetamide-5-amino-3(1-propoxy ethyl ester)-1-cyclohexene-1 carboxylic acid ethyl ester phosphate)” has a specific inhibitory effect on the influenza virus. However, it is expensive and may cause vomiting, nausea, insomnia, headache, abdominal pain, diarrhea, dizziness, fatigue, nasal congestion, sore throat, cough and other side-effects.
Tamiflu's effect on patients with dysfunction liver or intestinal organ will be weakened as the medicine works through esterase conversion to active metabolite, thus playing an inhibition effect of neuraminidase. In addition, the patients with renal insufficiency should take the medicine with caution.
Traditional Chinese medicine believes that the turpinia montana leaf can clear away heat and toxic materials, relieve sore throat and diminish swelling as well as promote blood circulation and stop pain, so it can be used for acute tonsillitis and pharyngitis, sore throat and tumble pain. Ligustroflavone, rhoifolin and hyperin are the main components of the turpinia montana leaf.
With the function of nourishing liver and kidney, improving eyesight and blackening hair, the ligustrum lucidum is mainly used for curing vertigo and tinnitus, soreness of waist and knees, premature whitening of hair, blurred vision and weakness of eyesight. Thus, it is mainly used to treat chronic bronchitis, hepatitis, hyperlipidemia, diabetes, menopause syndrome, infertility and atherosclerosis in recent years. Ligustroflavone is one of the main components of ligustrum lucidum. With the functions of dispelling cold, eliminating dampness, promoting circulation of qi and dissolving phlegm, the pummelo peel is used in the treatment of cold cough, throat itching, excessive phlegm, dyspepsia and vomit. Rhoifolin is one of the essential ingredients of pummelo peel. With the functions of soothing the liver, clearing heat and promoting diuresis as well as relieving swelling and pain, the hypericum perforatum is used for negative emotion, qi stagnation and depression, joint swelling and pain and difficult urination. As one of the key components of hypericum perforatum, the hyperin has shown a good protective effect on myocardial ischemia reperfusion, cerebral ischemia reperfusion and cerebral infarction and has the functions of analgesia, antioxidation, myocardium and liver protection. However, there's no proof that turpinia montana leaf and its contained ligustroflavone, rhoifolin and hyperin, the ligustrum lucidum and its contained ligustroflavone, the pummelo peel and its contained rhoifolin as well as the hypericum perforatum and its contained hyperin possess the functions of inhibiting the infection and reproduction of influenza virus as well as inhibiting the neuraminidase.